Deep brain stimulation (DBS) helps control Parkinson's symptoms

Cheng Xiu Xu was diagnosed with Parkinson's disease in 1997 at age 54. So, she is certainly no stranger to the challenges this progressive movement disorder brings. A native of China, Xu found that her quality of life was decreasing dramatically as years passed, with her tremors and other symptoms worsening despite frequent medication changes. Eventually, it became difficult or impossible for her to perform familiar activities, including playing her favorite sport: ping-pong.

"Medications often control symptoms like tremors, stiffness, slowness in movement, and some gait difficulties — at least at first," Xie said. "But as the disease progresses, patients usually require larger doses of medication, taken more often. Both symptoms and side effects often increase dramatically. Managing medications becomes a delicate process that requires close communication between patient and physician."

Unfortunately, in Xu's case, both the Parkinson's disease and its side effects had become too much for her and her neurologist to handle effectively.

"At first, the medications worked, but then they stopped working. That's when my doctor in Chinatown suggested I come to the University of Chicago Medicine," she said. "I was so happy when I met Dr. Xie because he is so smart and kind. The fact that he is Chinese means I can communicate with him directly."

When a patient with Parkinson's disease comes to Xie, he starts by adjusting medications, even if the patient has already been treated for the disease for years. "If there is a medical solution, it is always best to pursue that first, especially with a disease like Parkinson's that worsens over time," he said.

"But in Ms. Xu's case," Xie explained. "She came to us with severe motor fluctuation, dyskinesia and medication side effects. Her symptoms and side effects were so debilitating that we needed to take more drastic action soon."

Fortunately, as medical director of the deep brain stimulation (DBS) program at UChicago Medicine, Xie partners with neurosurgeon Peter Warnke, MD, director of stereotactic and functional neurosurgery. Xie and Warnke offer deep brain stimulation to patients who have movement disorders, such as Parkinson's disease, dystonia or essential tremor. DBS involves placing one or more small electrodes into the brain. This technique delivers direct electrical stimulation to targeted neurons, helping the brain to better control body movements.

In China, there is a saying that, if you want to live, you must keep moving. Now I can do that, thanks to Dr. Xie. — Cheng Xiu Xu

After careful consultation, Xie and Warnke decided that Xu was a good candidate for DBS.

"My life had gotten so bad I couldn't even get a glass of water for myself. I no longer wanted to live," the patient said. "But after I thought about it a lot, I decided surgery was my best chance to have a better life."

Xu's initial experience with DBS was positive but not ideal. "During surgery, we could see that her tremors disappeared instantly with the correct electrode placement, which is typical with DBS," Xie said. "But she still could not walk well with the initial activation of the DBS device due to 'freezing of gait,' which concerned us."

According to Xie, DBS typically helps all Parkinson's motor symptoms except for difficulties with gait, balance and swallowing dysfunction. "In particular, freezing of gait leaves patients suddenly feeling like a magnet is stuck to their shoes when they attempt to walk," he said. "Patients are vulnerable to loss of balance and falling forward, so this is particularly dangerous."

Xie recalled a published study finding that patients who developed freezing of gait after several years of DBS improved when their physician reprogrammed their devices from the commonly used 130 Hz to 60 Hz. Although this technique had not been tried in a patient who developed sudden freezing of gait with a newly activated DBS device, he believed it would work with Xu. "Her gait became normal within seconds of me changing the DBS frequency to 60 Hz," he said. "She walked out of my office. It was so exciting for both of us."

Since then, Xie and Warnke have published their findings and successfully used the lower 60 Hz frequency on a dozen or so DBS patients who, like Xu, experienced freezing of gait. They are the first team to consider two exciting hypotheses — that DBS may actually help freezing of gait and that freezing of gait may not necessarily be a long-term effect of DBS. Xie and Warnke also find that the lower frequency helps improve the patient's voice and swallowing functions. The pair have additional studies under way.

As for Xu, all she knows is that her DBS surgery has transformed her life. "A couple of years ago, I wanted to die," she said. "Then, two days after Dr. Xie adjusted [my implant] I was back playing ping-pong, which brings me so much happiness."

Managing Parkinson's

As Parkinson's disease progresses, patients may experience side effects such as hallucination, confusion or dizziness with a drop in blood pressure. Body movements may become gradually difficult and even impossible to control, fluctuating between severe tremors, stiffness, and an inability to move when medication is "off," and severe involuntary movements (dyskinesia) when medication is "on."

Peter Warnke, MD

Internationally renowned neurosurgeon Peter Warnke, MD, has performed more than 5,000 stereotactic surgeries and more than 2,000 brain tumor surgeries. Dr. Warnke provides neurosurgical care for the treatment of adults and children with movement disorders, epilepsy and brain tumors.